Scriptaid affects histone acetylation and the expression of development-related genes at different stages of porcine somatic cell nuclear transfer embryo during early development

Although the somatic cell nuclear transfer (SCNT) technique has been used extensively for cloning and generating transgenic pigs, the cloning efficiency is still very low. It has been proposed that the low efficiency of this technique is the result of incomplete epigenetic reprogramming and abnormal gene expression during early embryonic development. In this study, we investigate the effect of Scriptaid, a low-toxicity histone deacetylase inhibitor, on the developmental competence of porcine SCNT embryos. We found that treating SCNT embryos with 500 nmol/L Scriptaid for 15 h after activation significantly enhanced the blastocyst formation rate (27.7%) compared with the untreated group (control) (12.2%, P < 0.05). Using an immunofluorescence technique to measure the average fluorescence intensity, we also found that treating SCNT embryos with Scriptaid increased the level of histone acetylation on histone H3 at lysine 14 (acH3K14). Furthermore, treating embryos with Scriptaid increased the expression level of three genes that play important roles during embryonic development (Oct4, Klf4 at the blastocyst stage and Nanog at the 4-cell stage). Moreover, the expression level of the apoptosis-related gene Caspase-3 was significantly lower in the Scriptaid-treated SCNT embryos compared with the control SCNT embryos at the 4-cell and blastocyst stages. In conclusion, these results indicate that Scriptaid treatment improves the development and nuclear reprogramming of porcine SCNT embryos.